I'd like to know what's the error message. We can reset it if you forgot your User ID or Password. Let me show you how.
Go to the Merchant Service Center and click the Can't access your account? Choose any of the recovery options and follow the on-screen instructions. Once done, log in again to the GoPayment app using the new login credentials.
If you see the "Sign In Failed" message, we can fix it by updating the app. Visit Google Play or App Store to install the latest release.